Law enforcement officer by day, hot rodder by night—Robert Foley always wanted to get his hands on an early Mopar Max Wedge car.

Robert Foley always wanted to put together an early big-block Mopar muscle car. “I liked the history and tradition, how these awesome cars put Chrysler into the forefront! I lucked out and found a 1963 Dodge Polara with the awesome 426 Max Wedge already in it!” The clone-conversion is about as close as an average hot rodder can get to the real McCoy outside of a museum. Its frame-off rebuild included a real 13.5:1 426 Max Wedge motor, complete with a solid-lifter cam, a cross-ram fed by Edelbrock AVS carbs, and factory cast-iron headers. The power is transferred back through a 3,000-rpm stall-speed converter, a pushbutton 727 TorqueFlite, and a 3.91:1-geared Moser 8¾-inch Sure-Grip.

Originally a 318-powered dozer, the Polara underwent a rotisserie restoration, complete with an authentic 426W motor.

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Even back in the day, these raggedy-edge cars weren’t known as stellar coolers. Today’s crappy gas sure doesn’t help things. “I couldn’t drive it more than 2 to 3 miles before the temperature would get up to 220 degrees,” Foley complained. “At that point, I’d just shut it off. It never stabilized or leveled off, wouldn’t improve at high speed, and didn’t care what the outside temperature was.”

The stock cooling system couldn’t cool the 13.5:1 426. Note how the radiator, shroud, fan, and engine mount are offset to the passenger side.

The Diagnosis

Rollings’ Automotive dropped in a new Griffin “Combo Package”: a high-tech aluminum radiator with twin electric fans in a custom shroud.

Fortunately, Rollings Automotive—one of our go-to SoCal rescue facilities—is within spitting distance of Foley’s Riverside, California, residence. Norm Rollings took only a few minutes to science the problem out. There were no obvious mechanical defects: The thermostat was opening, the pressure cap was the system’s high point, there were no bubbles in the coolant, and timing adjustments made little difference. Time to bring out the big guns: an aluminum radiator, electric fans, and a high-flow water pump. The electric fans’ electrical demands called for a higher-output alternator and wiring upgrades. Added into the mix was Foley’s wish to preserve (to the extent possible) the Polara’s period looks. We spec’d the 440Source.com for a water pump, Griffin Thermal Products for the radiator and fans, Powermaster for a high-output alternator, and a posse of local and aftermarket manufacturers to deal with the inevitable chassis integration and detailing requirements.

It’s not easy keeping a 13.5:1 all-cast-iron 426 Max Wedge cool on the street. The three big-ticket cooling rescue items include a Griffin aluminum radiator/shroud/electric fan package, a 440Source.com high-flow aluminum water pump with cast-iron impeller, and a modern 95-amp Powermaster one-wire alternator. But there’s lots of little extras that make for a sano upgrade, including dipping into Rollings’ secret stash of aircraft fasteners. If there’s no surplus store in your area, most of the “trick” hardware can be purchased from outfits like Aircraft Spruce or ARP.

A] Water pump (Photos 01–03)

B] Radiator, electric fans (Photos 04–10, 13–14, 25–26)

C] Coolant recovery tank (Photos 11–12)

D] One-wire alternator (Photos 15–18)

E] Disconnect external regulator (Photo 19)

F] Fan controller and fan relays (Photos 20–21, 23)

G] Aircraft hardware (Photos 21–22)

H] Starter relay (photo 24)

I] Shorter oil filter (Photo 21)

The Fix: Water Pump

Big-block Chryslers use a water pump that bolts to a separate housing that in turn bolts to the engine block. The pump’s impeller-blade shape plus the clearance of the pump/impeller assembly to the housing’s interior cavity is an important factor in establishing the pump’s overall efficiency. Foley had a standard cast-iron housing and the usual parts-store cast-iron pump with sloppy clearances; the cheapie sheetmetal impeller looked like it was cannibalized from a child’s toy. They were trash-canned and replaced by 440Source.com’s high-flow aluminum pump and housing kit. The pump features a superior curved-vane cast-iron impeller, and the close-tolerance interior housing clearances are precisely controlled to the point that 440Source.com supplies its own pump-to-housing gasket (yes, paper gasket thickness can vary slightly).

01] The 440Source.com’s high-flow aluminum pump with its matching tight-tolerance aluminum housing tightens up the impeller-to-housing clearances for better flow.02] Note the 440Source.com’s curved-vane, cast impeller, as well as a thick shoulder that extends further into the housing (right); the stocker (left) has a flimsy sheetmetal impeller—ouch!03] 440 Source’s “early” pump has the right driver-side inlet and enough hot-side pipe-thread holes to allow mounting (from left) the stock temp sender, an Auto Meter temp gauge sender, and the electric fan control unit thermal probe without tee-fittings. Buttonhead pump-to-housing screws clear large billet pulleys. The 440Source.com’s billet water outlet hides a Rollings-gutted thermostat—this is Southern California!

The Fix: Radiator and Fans

To replace Foley’s copper/brass three-row radiator and lame four-blade mechanical fan, we chose Griffin’s Exact Fit aluminum two-core radiator that’s designed to drop in place of most original old-school radiators. In this case, the exact year and model weren’t in the catalog, but a close analog is listed for other 1962–1965 big-block Mopar muscle cars; just be sure to check exact fitment and clearances. Foley’s existing, nearly new upper and lower radiator hoses bolted right up.

04] Radiator tech has come a long way since the 1960s. Griffin’s Direct Fit Combo kit package for most early Mopar big-block/auto-trans cars (PN CU-70024) includes its high-tech aluminum radiator plus a custom aluminum shroud loaded with twin SPAL 10-inch electric fans. The large tube, high-density core still uses a sheetmetal tank for a pseudo-classic appearance. The numbered callouts in this photo indicate the “real-world” location of the parts shown in photos 00–00 that follow within this “Radiator and Fans” section.05] Like many current OE setups, shroud-relief flaps open at speed to relieve detrimental pressure buildup.06] A good idea for any aluminum radiator, Rollings added an anti-corrosion sacrificial anode in place of the conventional drain cock.07] Not inverted flare or 37-degree AN: Rare ¼ pipe-thread-to-SAE 45-degree male cone nipples connect the stock ⁵⁄₁₆-inch auto-trans hardlines to the radiator.08] Griffin uses pipe thread for the overflow nipple below the pressure cap, allowing Rollins to bend up a ¼-inch stainless-steel hardline with a 37-degree AN coupling nut and flare.09] At the other end, the tubing connects to Phenix lightweight race hose using a Phenix flareless compression fitting, eliminating the need for an extra union.10] Always check hood clearance using modeling clay or heavy grease. Rollings had to lower the radiator ½ inch, accomplished by drilling new holes in its integral mounting plate ½-inch higher to mate with the core support’s factory holes and weld nuts (arrow).

A big Moroso reservoir tank reported for duty as a coolant recovery unit.

11] The Phenix race hose runs from the overflow tube (see photo 09, above) to the bottom of this big 2-quart Moroso aluminum reservoir tank. It’s used here as a full sealed coolant recovery system (CRS). Rollings says the tank in most retrofit CRS kits is too small. “Judge for yourself. Look how large today’s overflow tanks are on new cars.”12] The Moroso tank mounts to existing factory weld-nuts on the driver-side fender via a fabricated aluminum bracket.

So what’s so special about Griffin’s aluminum wonder? Dimensionally, the core height and width is about the same as the old unit, but aluminum’s higher tensile strength allows the tubes to be significantly larger, resulting in more surface area per tube—and surface area is where most heat exchange goes down. Griffin has a higher tube density/inch, further improving heat dissipation when used with electric fans and a properly designed shroud.

13] Griffin’s 18.00 x 21.88-inch core area is about the same as the old radiator, but there’s more to radiator efficiency than gross dimensions. Theoretically, a copper/brass radiator is a slightly more efficient heat exchanger than aluminum, but its tensile strength is lower. Being stronger, aluminum supports higher pressures and larger-diameter, thinner-wall radiator tubes. The Griffin used on the Polara has 1.25-inch tubes, but despite its larger tubes, the Griffin’s tube density comes in at 54 tubes/inch.14] By contrast, the stocker it replaced has only 0.375-inch tubes and 39 tubes/inch. This makes the Griffin’s tube density about 38-percent higher than the stocker. Griffin also has 16 fins/inch, versus this old unit’s 13 fins/inch. Collectively, larger tubes with greater surface area plus higher density greatly increase heat dissipation.

Then there’s the issue of multirow (multicore) stacking: On an old three- or four-row radiator, the rear cores are less efficient because they see air that’s already been heated by the forward core(s). A similarly sized two-core aluminum radiator with larger tubes nearly always outperforms a three- or four-core copper/brass setup. And electric fans perform best on a radiator with fewer cores. Unlike a beltdriven fan whose speed is tied to engine rpm, electric fans run at a constant speed independent of engine rpm, making them today’s choice for superior low-rpm cooling on most hot rods.

We ordered the Griffin’ radiator as part of a complete “Combo Package,” which also includes a custom shroud, twin SPAL electric fans, and relays. But those current-hungry fans and Foley’s existing electric fuel pump gotta get fed.

The Fix: Alternator and Wiring

15] Out with the weak stock alternator. A Powermaster high-output, one-wire unit supplies the new Griffin-supplied electric fans’ current demands.

Old muscle cars were underwired even stock, and first-gen alternators didn’t put out enough current at idle. (Ever experience dim headlights when idling with the windshield wipers on?) As alternators evolved, they became more efficient, developing higher peak output in a similar-size case, putting out more amps at idle, and ramping up to full power quicker. At speed, early Chrysler alternators typically put out at most 50 amps. We were able to more than double that with a bolt-in, Chrysler-style Powermaster one-wire unit. They’re officially rated at 95 amps, but the dyno-test sheet in the box showed our unit actually made 75 amps at idle, 80 at cruise, and 112 on the top end.

16] Fan appreciation day: Supplying current to the grateful, current-hungry, electric fans is a Powermaster one-wire squareback alternator (right) that’s at least twice as powerful as the first-gen roundback it replaced (left). The new unit’s case is based on the mid-1960s-and-later Chrysler configuration, but still looks distinctively Mopar. It physically bolted up with no reclocking needed.17] Powermaster’s true one-wire unit is internally regulated and self-exciting. Don’t connect any of the old external wires to the Field terminals (A). Bolt the single charge wire to the B+ stud (B). The alternator usually self-grounds through its mounting bracket, but for insurance Rollings ran an external ground wire from the ground terminal (C) to an exhaust manifold bolt.

Powermaster’s internally regulated design is a cinch to install. It uses just one main charge wire. Rollings did upsize from a 12-gauge to a Powermaster 8-gauge charging wire, protected from chafing (as were all the other newly run wiring) by split nylon sleeving. Foley was already running a AWG 00 battery cable from his trunk-mounted battery to the starter.

18] Upgrade the charge wire from the typical 12-gauge stocker to 8-gauge (or larger, depending on the length of the run); they’re available from Powermaster. Here the upgrade runs to the starter relay and on to the starter. Still running a stock ammeter? Hook the black wire to the B+ stud. Run an auxiliary ground as desired.(Photo: Ryan Lugo)19] The old separate voltage regulator was left sitting on the firewall for looks, but it’s not hooked up to anything.

To reduce potential duty-cycle strain under California 100-degree-plus summers, Rollings elected to use 75-amp Bosch fan control relays in place of the supplied 30-amp units. A Hayden adjustable fan controller allowed dialing in the fan actuation temperature as measured by a thermal probe that safely screws into a water pump pipe-thread fitting.

20] Rollings fail-safed the car against SoCal’s blazing summer heat: “I installed 75-amp Bosch relays (left) in place of the supplied 30-amp relays (right). As the outside air temp goes up, the wires get heat-soaked, increasing resistance and amp-draw, so you have to derate the official specs.” On the car, they mount to the core support using Nutsert rivet nuts.21] Rollings added a Hayden adjustable fan controller with a pipe-threaded thermal probe. “It’s safer than an all-metal probe slid through the radiator fins, where you can have a direct short to ground if there’s ever metal-to-metal contact.” The Hayden mounts with surplus aircraft “pin screws” that have a wrenchless flat head and an internal wrenching hex at the externally-threaded end. This allows tightening a self-locking jet nut from one side.22] If there’s a trick way to attach something, odds are good you’ll find a solution at your local aircraft surplus hardware store. Jet nuts and pins screws come in an almost infinite variety of variations.23] The Hayden controller triggers two big 75-amp Bosch relays. Each Bosch relay runs one fan. The Hayden unit has its own 30-amp relay, but it’s not stressed because, in this installation, its “high side” serves only as a low-current trigger for the two larger Bosch relays. Fusible links provide further protection.(Photo: Ryan Lugo)24] Main power feeds for the electric fan relays and fan controller comes off the Chrysler firewall-mounted starter relay. Fusible links (which did not exist in 1963) were added after this photo was taken for circuit protection.

The Fix: Final Clearance Issues

After everything was buttoned together, Foley’s existing oil filter hit a transmission fluid cooling line. Rollings replaced it with a shorter filter used on many late 1990s Chrysler products. There was also some concern about limited clearance between the fans and water-pump pulley. However, it proved not to be a problem even when the engine “rocked-over” under hard acceleration. All in all, everything fit together like a large jigsaw puzzle.

Foley’s Polara runs normally at 185 degrees under normal driving, rising to no more than 205 degrees when he gets real squirrely and performs multiple burnouts. Rollings plans some additional fine-tuning to get the dinosaur motor to behave a little better during daily street driving, though we expect the 13.5:1 mill will always need additive.

Lessons Learned

If you really want to drive a classic, high-compression, muscle-car clone on the street, be prepared to implement modern tech to keep it alive. On some of these cars—especially those cloned from a more sedate model—not everything is as it’s “supposed to be.” Be prepared to check fitment on every add-on, and don’t be afraid to mod as needed so everything fits together like it should. That’s hot rodding!

The only heat the now-cool, bright-yellow Polara generates is the rumpity-rump of the never-to-be forgotten age of big Detroit muscle.

Need Junk Fixed? If your car has a gremlin that just won’t quit, you could be chosen for Hot Rod to the Rescue. Email us at pitstop@HotRod.com and put “Rescue” in the subject line. Include a description of your problem, a photo, your location, and a daytime phone number.